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v 3 Sheets-Sheet 1. J. S. TROTT. ELEVATOR (No Model.)

Patnted 0013 15,

(Nd Model.) 3 Sheets-Sheet 3.

' J. S. TROTT.

- ELEVATOR.

No. 547.972. Patented Oct. 15, 1895.

UNITED STATES PATENT OFFICE.

JOSEPH S. TROTT, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO EDWARD F.BROOKE AND SAMUEL W. BROOKE, OF SAME PLACE.

ELEVATOR.

E-lPECIFIGATION forming part of Letters Patent No. 547,972, datedOctober 15, 1895.

Application filed December 1, 1894- Serial No. 530,577- (No model.)

To all whom it may concern.-

Be it knownthat I, JOSEPH S. TROTT, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Elevators, of which thefollowing is a specification.

My invention relates to improvements in elevators or lifts for passengeror freight service.

My object is, first, to provide an elevator of improved constructionemploying compressed air as the motive power; second, to providecompressed-air counterbalance mechanism for the elevator car orplatform, which shall operate in the descent of the latter not only as acounterbalance, but also as means for recharging the compressed-airreservoir.

In the drawings, Figure 1 is a broken sectional view, partlydiagrammatic, illustrating my improvements; Fig. 2, an enlarged brokensectional view of one side of the car and adjacent wall of theelevator-shaft, illustrating my improved safety mechanism; Fig. 3, anenlarged section taken on line 3 of Fig. 2; Fig. 4, a partly sectionaland partly bottom plan view of the elevator-car, the section being takenon line 4 of Fig. 1; Fig. 5, an enlarged section taken on the irregularline 5 of Fig. 4; and Fig. 6, an enlarged sectional view, partlydiagrammatic, illustrating counterbalance switch mechanism, the sectionbeing taken on line 6 of Fig. 4 and viewed in the direction of thearrow.

A is an elevator shaft or hatchway; B, an air-motor; O, a compressed-airreservoir, and D an elevator-car. The car D comprises a frameworkconsisting of a platform D, vertical side, bars D D and a top beam D andmounted in the frame is a cage D all being substantially of theconstruction usually employed for passenger service.

E is a cable rigidly secured to the beam D and extending over a pulleyEat the top and center of the shaft and thence to the motor.

-F is a main or working cable secured at its end to a vertical bar F,which passes loosely through the beam D and is fastened at its lower endto a spring F in a common man ner. The cableF passes over a pulley Fadjacent to the pulley E, and thence to the motor B. The pulleys F E areat an acute angle with relation to each other, so that the cable E inFig. 1, where it extends from the pulley E to the motor, is directlybehind the cable F and hidden thereby. The motor has a piston-cylindert, communicating through a pipe i with the compressed-air reservoir O.The piston in the cylinder is upon the stem .9, carrying pulley-wheelss", the outer end of the stern being upon a carrier 3 which travels uponguide-tracks s Mounted at the opposite end of the cylinder are pulleys3, extending at their peripheries to the central line at one side of theelevator-shaft. The cables E F extend around the pulleys s 5, wherebyoutward movement of the pistonstem 8 with the pulleys 8' draws upon thecables to lift the car, and inward movement of the piston-stem andpulleys s relaxes the cable and causes the car to descend. The motor Band its attendant parts described may be of a construction in the mainhitherto employed for elevators using steam as the motive power, and nodetailed description in the present connection is thought to benecessary. The compressed-air reservoir 0 connects by means of a pipe rwith an air-compressor Z. Interposed in the pipe 15 is a three-way valveoperated by a wheel or pulley t to direct air from the air-reservoir tothe cylinder 15 to force the piston and attendant parts outward, or toclose said communication and open thecylinderto the outside air, wherebythe weight of the car causes the piston and attendant parts to travelinward, or to close communication between the cylinder and both theair-reservoir and outside air, whereby the piston and attendant partsremain at a standstill to hold the car at any elevation at which it isstopped. The said valve may be operated from the car through the mediumof a rope or cable 15 passing around the said pulley t at the bottom ofthe shaft and a pulley t at the top of the shaft, the rope or cableextending through the car in a common manner and provided near the topand bottom with stops 6 25 respectively, which, when engaged by the car,cause the cable to be moved by the travel of the car to the position ofclosing the valve.

At opposite sides of the car and forming part of the shaft constructionare vertical guides G G, extending from the bottom to the top of theshaft. Each guide is formed of wood and is provided at its center withan inward-projecting tongue q, a laterally-projecting tongue or guide qat one side, and a laterally-projecting tongue or guide (1 at itsopposite side. On the under side of the car are two pairs of hangers p pand p p, in the relative positions shown, provided with elongatedbearing-openings 19 (See Fig. 6.) Extending near opposite end portionsthrough the bearing-openings p of the hangers p is a shaft H, andextending toward opposite ends through the bearing-openings 19 0f thehangers p is a shaft H. Rigidly secured to the ends of the shafts H H,beyond the sides of the car, are friction-wheels 02, having, preferably,grooved peripheries, which embrace the tongues g g of the guides G G.

H is a leverfulcrumed at n to the under side of the car-platform andconnected at its short end by means of a link 72 with a yoke H near thecenter of the latter, the yoke being provided at opposite ends withbearings M, which loosely engage the shaft H adjacent to the hangers 1).At the opposite side of its fulcrum the lever H is connected by a link awith a yoke H of the same construction as the yoke I1 and engaging theshaft ll adjacent to the hangers 1). Turning of the lever H at its longarm in one direction causes the yokes H H to be drawn toward each otherand move the shafts II H in the bearing-slots p to clamp the guides G Gbetween the friction-wheels n, the latter being pressed firmly againstthe tongues q (1 At the center of each shaft H H is an cecentric-disk m,which revolves in the ring or stirrup of a pitman m. Adjacent to eachdish m at opposite sides of the platform are pump-cylinders I I, eachcontaininga piston 1 upon a stem 1 pivotally connected with the adjacentpitman m. The pumps may be either single-acting or double-acting, thoughthe one shown in Fig. 4 is of the single-acting type, having each aninlet-pipe Z, provided with a check-valve Z, and an outlet-pipe Zprovided with a check-valve Z Extending from the air-reservoir O to theelevator-shaft, at a point about half-way between the upper and lowerends of the latter, is a pipe 0, from the end of which extends aflexible hose C connecting by means of branch pipes C with thedischarge-pipes Z of the pumps I I. Fulcrumed between its ends at Itupon the car is a shipping-lever H at its lower end pivotally engagingthe end of the long arm of the lever H In the upper part of the car is acylinder K, containing a piston K, having a stem K which connectspivotally with the upper end of the lever H Extending through the head Kof the cylinder K is a pipe K communicating with one of the branch pipes0 Interposed in the pipe K is a three-way valve K, which may be turnedto direct pressure from the pipe K into the cylinder K, or close saidconnection and open the cylinder to the outside air.

The valve K is provided with an operatinglever K Extending throughguides 2' 11 on the ear is a vertical and reciprocatory rod L, connectedby means of a link L with the said operating-lever K. The lever L isprovided with a counterbalance L which may comprise a cord or otherflexible medium connected with the rod, extending over a pulley andprovided with a weight, as indicated in Fig. 6. In the cylinder K is aspring K which tends normally to press the piston K in the direction ofthe head K The rod L extends at one end through the top of the car andat its opposite end through the floor of the car, and the beam X at thetop of the shaft,which supports the pulleys F E 15 extends across thepath of the upper end of the rod L, and a beam X at the lower endportion of the shaft extends into the path of the lower end of the rodL.

In the rise of the ear to the top of the shaft theupper end of the rod Lstrikes the stop X and is plunged downward, whereby through the link Land the lever K the valve K is opened to direct air air-pressure intothe cylinder K, and thereby cause the piston to be moved against theresistance of the spring K to turn the shipping-lever H and lever 11whereby the shafts H H are moved in the direction of each other and thefriction-wheels n are caused to clamp the tongues q (fof the guides G G.

In the descent of the car tl1e rod L strikes the stop X and is movedupward to turn the valve K and vent the cylinder K, whereby the spring Kmoves the piston in the direction of the head K and turns the levers llH to move the friction -wheels at in the direction away from each otherto release the tongues q (1 In operation the airreservoir is keptcharged by means of the compressor, and the motor is operated throughthe medium of the rope or cable t to raise and lower the car. In therise of the car the friction-wheels n are disengaged, as described, fromthe guides G G and the pumps I I are quiet. In the de scent of theelevator, however, the frictionwheels 01 are caused to clamp the guidesG G, and by their frictional engagement therewith cause the shafts H Hto rotate and operate the pumps, whereby air is compressed and forcedthrough the pipes C C (J to the reservoir 0. Thus the descending forceof the car operates as supplemental charging means for the air-reservoirC, and the frictionalengagement of the wheels at with the guides G G,owing to the resistance at the pumps I I, operates as a counterbalanceto the car. In op eration, therefore, the pressure taken from thereservoir G to lift the car is replenished to a material extent by thedescent of the car, and the action of the main compressor mechanism isthus greatly relieved. It will be understood, of course, that the objectof reducing the action of the compressor is to economize in the steamand fuel employed for operating it. Fulcrumed between its ends on thebeam D is a lever M, pivotally connected-at one end with the rod F andat its opposite end pivotally connected with a vertical rod M, whichextends down the side of the car. At the lower end of the car at itsside is a recess having an inclined rear wall M In the said recess is awedge-block M having an inclined rear face and provided at its oppositeside with a serrated face M The block M has a stem M which works throughan opening in a bearing-bracket M fastened to the under side of the car.Around the stem and confined between the lower end of the block andbracket M is a spring M The serrated face of the block M moves normallyclose to but out of contact with the tongue g on the guide G, the weightof the elevator-car causing the spring I? to be drawn in the directionof the beam D whereby the lever M is normally turned to the positionshown to press the block or dog M downward on the inclined guide formedby the wall M of the recess. In the event of breakage of the cable F thespring F will expand in the downward direction and swing the lever M inthe direction of raising the rod M and block or wedge M in the inclinedguide, causing the serrated face M to grip and become bound against theadjacent edge of the tongue q. The engagement of the serrated face ofthe wedge with the face of the wooden tongue q will stop the descent ofthe car and hold it with great security.

What I claim as new, and desire to secure by Letters Patent, is-

1. In an elevator, the combination with the hatchway, of a car,operating means therefor comprising an air-motor, cable connecting thecar with the motor and a compressed air reservoir for supplying themotor, a main air compressor connected with the said reservoir andsupplemental air compressing means upon the car comprising an air-pumpconnected with the said reservoir, an operating shaft for said pump,wheels upon the shaft, longitudinal and stationary bearing guides in thehatchway, and means upon the car for clamping the said wheels againstthe said hearing guides, whereby movement of the car causes operation ofthe pump thereon, substantially as and for the purpose set forth.

2. In an elevator, the combination with the hatchway, of a car,operating means therefor comprising an air-motor, cable connecting thecar with the motor and a compressed air reservoir for supplying themotor, a main air compressor connected with the said reservoir andsupplemental air compressing means upon the car comprising an air-pumpconnected with the said reservoir, an operating shaft for saidpump,friction-wheels upon the shaft, longitudinal and stationary bearingguides in the hatchway, movable shifting mechanism, upon the car, forthe frictionwheels operating, when moved in one direction, to clamp thefriction-wheels against the said bearing guides and cause working of thepump by movement of the car, and operating, when moved in the oppositedirection, to release the friction wheels from the bearing guides,movable shifting-mechanism actuating-means projecting from the car, andstops in the hatchway, toward opposite ends thereof, in the path of thesaid actuating means, whereby in the rise of the car the frictionwheelsare released from the said guides and in the descent of the car theyengage the said guides, substantially as and for the purpose set forth.

3. In an elevator, the combination of a hatchway, having longitudinalbearing guides, an elevator-car, a com pressed-air reservoir, a motoractuated by air-pressure from said reservoir to raise the car, means forcounterbalancing the car, comprising an air-pump on the car connectedwith the reservoir, and pump operating means on the car, actuated by thedescending movement of the car, substantially as and for the purpose setforth.

4. In an elevator, the combination of ahatchway having longitudinalbearing guides G G, an elevator-car, a compressed-air reservoir and maincompressor connected therewith, a motor actuated by air-pressure fromsaid reservoir to raise the car, pumps on the car connected with thesaid reservoir, parallel operating shafts for the pumps, friction wheelson the shafts at opposite sides of said guides, lever mechanism on thecar connected with the shafts for moving the friction-wheels into andout of engagement with the said guides, substantially as and for thepurpose set forth.

JOSEPH S. TROTT.

In presence of- M. J. FROST, J. H. LEE.

